get ViewportDialog to display as a part of machine transition

platform/viewer/src/appInit.js

@@ -6,6 +6,7 @@ import {
   UINotificationService,
   UIModalService,
   UIDialogService,
+  UIViewportDialogService,
   MeasurementService,
   DisplaySetService,
   ToolBarSerivce,
@@ -44,6 +45,7 @@ function appInit(appConfigOrFunc, defaultExtensions) {
     UINotificationService,
     UIModalService,
     UIDialogService,
+    UIViewportDialogService,
     MeasurementService,
     DisplaySetService,
     ToolBarSerivce,